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While calibrating the injectors you should let the AFR stabilize at 14.7 at idle by adjusting deadtimes after which you let the AFR stabilze at 14.7 by adjusting the injector constant while cruising at a stable RPM at constant speed and so on. Don't take it for a pull in the meanwhile.

Turn the aircon off while calibrating, especially when idling.

 

Are you sure there aren't any vacuumleaks?

 

Edited by Piet
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I am absolutely positive,no vacuum leaks. Intake 22mm Hg when idling. I tried the tuning the dead times,but it's very unconsistent. With the same injector constant (around 0.77), with a dead time of 0.65 AFR is 13.5, and with a dead time of 0.6 it drops to 16 ! Tried with 0.625 from 12V to 14V and i get 15.5-15.7 ! I am then running out of resolution. 

My guess is that maybe the alternator is playing jokes on me, as in the first minutes after starting the engine, it charges around 14.2V, and then drops slowly to 13.2-13.5V... Charging relay is a new Mobiletron. :(

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The values I got after calibrating my greens were 0.75 as an injector constant and 0.5265 as deadtime.

I keep my injectorvoltage at a solid 14 volts with a step up converter.

Edited by Piet
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Midnight, how are the fuel trims while driving vs idle?, i had an issue with this for a bit, found a small leak which was making my AFR end up way off while city driving vs highway.

idle trims will tell the tale!

 

edit: it also would explain why engine temp plays a part in this.

Edited by Stevo11811
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.7188
 

9.085129
5.269096
3.247022
2.185053
1.693258
1.388571
1.153116
1.055722
0.970821
0.895956
0.822444
0.762411
0.701862
0.645228
0.604411
0.588644

 

These values are direct from the Bosch calibration documents. I disagree with the method of injector tuning advocated in this thread. If you have injectors that come with detailed calibration specifications, then you should use those. If you have high fuel trims resulting from those values, then you should look at hardware issues, not adjustment of the injector values to compensate.
 
Are these verified genuine green injectors? I've dealt with a few people and knock green injectors and they give all sorts of problems.

When the car is warm, idling at 840RPM and the AFR is between 14.5-14.9, what is the measured air consumption?

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The injector tuning does give very good results though. When still running narrow band it give me very good and stable fuel trims and I assure you my hardware is in top condition. The greens I use are genuine Bosch.

Also with others we achieved good results with it.

 

An injector constant of 0.71 is pretty low for these 449 cc/min injectors.

Are you sure these numbers are for gasoline? Bosch has not the habit to express injectiorparameters for gasoline. They generaly use N-Heptane for that.

Edited by Piet
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Midnight, how are the fuel trims while driving vs idle?, i had an issue with this for a bit, found a small leak which was making my AFR end up way off while city driving vs highway.

idle trims will tell the tale!

 

edit: it also would explain why engine temp plays a part in this.

hm so the tiny leak I have in my intake pipe post maf could be the result of my fuel trims being all wacky. Drove to Colorado and all was fine until I started to idle after the trip my car was running so rich I was just dumping fuel. Aaron and I discussed this and it makes sense as well. Just confirming what you're saying Steve is 100% correct. A tiny tiny leak can really mess with things. 

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No, I can reconfirm, first thing I tried was to check for leaks. I was using the whites and had to use a lower constant than was even in the original BIN ! When using whites, original constant was 0.906 and to have a steady AFR I had to dial in a constant of around 0.88, maintaining the stock bin whites dead times. So definitely I don't have a leak, otherwise I should have had to use a higher injector constant in the first place, right ? I have no other hardware mods from then to now.

When first putting greens, using the whites constant and dead times, first start gave me an AFR of 12.9-13, so they are definitely bigger :)

When accelerating, if I use the accelerator pedal around 10%, AFR goes to over 16 and then returns to 15.5-15.6. If I press it a little more, to around 20%, AFR goes to 14.7-14.8 and from there it goes lower as I accelerate further. In other words, I have AFR issues with light loads, at higher loads AFR is ok. If I am cruising in 3rd at 60km/h let's say (I cannot drive at 90km/h in the city here), AFR stays at over 15. As soon as I press the accelerator (to get up in 4th), AFR goes to 14.7.

The injectors are genuine Bosch, not China knock-offs.

4.973
4.973
3.666
2.164
1.775
1.365
1.131
1.034
0.624
0.624
0.624
0.624
0.624
0.624
0.585
0.526

These are my dead times, with an injector constant of 0.7734. I only modified between 12V and 14V, the rest are the dead times from the whites

Edited by Midnight Caller
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An injector constant of 0.71 is pretty low for these 449 cc/min injectors.

Are you sure these numbers are for gasoline? Bosch has not the habit to express injectiorparameters for gasoline. They generaly use N-Heptane for that.

I run very close to these numbers for every engine running greens I tune. If there are no air leaks LTFT_PL stays under 4% and LTFT_I under 40ms. 

I believe gasoline was used for this test. I actually looked up the document again and I may be mistaken about it being from Bosch. It is however very complete and in depth.

Midnight Caller, can you answer my question?When the car is warm, idling at 840RPM and the AFR is between 14.5-14.9, what is the measured air consumption?

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About the injector calibration method:

Factory values are fine. But not par. 

Under wot or while accelerating it helps when the values are par. This is valid for WB and for NB controlled cars.

I agree with you Aaron, that the method Maarten and Piet described should not be used to compensate deteriorated components, but a perfect calibration makes a difference.

Besides: While tuning, we may have decided for a another pressure on the fuel rail or a better performing fuel pump. (like a Deatschwerks)

The ECU calculates beforehand the necessary amount of fuel to inject. So good injector calibration helps.

After the initial enrichment a wot situation or feedback regulation  will occur. With a NB, but also with a WB regulated system, you will see a difference in precision of control and performance.

-edit- My car is not too far of recommended values b.t.w.

Edited by razorx
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I will check again these days

Vida and the blue volvo service books state 12-14kg/h if I recall correctly. That's what I measured when using the whites and car ran ok. I'll verify again the check valves,one was defective last time I checked.

I can completely plug the evap circuit and see what measurements I get.

But even if i had a leak, how can be explained the fact that with the whites,I had to lower the injector constant because it was running too rich with the stock bin constant ? :)

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I will check again these days

Vida and the blue volvo service books state 12-14kg/h if I recall correctly. That's what I measured when using the whites and car ran ok. I'll verify again the check valves,one was defective last time I checked.

I can completely plug the evap circuit and see what measurements I get.

But even if i had a leak, how can be explained the fact that with the whites,I had to lower the injector constant because it was running too rich with the stock bin constant ? :)

Good question, but there is a few things off of the top of my head that i can think of, Inconsistent fuel pressure, inconsistent voltage, Small vacuum issue, Aaron could be correct also with a check valve issue, i have been in that position a few times with my car and always end up finding the smallest of things causing a headache.

On My girlfriends brothers car his Evap purge was sticking open slightly causing inconsistent AFR's and hard starts

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